// import Vuefrom from "vue";
import Vue from 'vue'
/*
*  使用方法*   给elementUI的dialog上加上 v-dialogDrag 指令就可以实现弹窗的全屏和拉伸了。*  给dialog设置 :close-on-click-modal="false" , 禁止点击遮罩层关闭弹出层*  如果是form表单，不要将提交等按钮放置el-form-item，以免在上下拉伸时被隐藏*/
// v-dialogDrag: 弹窗拖拽+水平方向伸缩

Vue.directive("dialogDrag", {
  bind(el, binding, vnode, oldVnode) {
    //弹框可拉伸最小宽高
    let minWidth = 400;
    let minHeight = 300;
    //初始非全屏
    let isFullScreen = false;
    //当前宽高
    let nowWidth = 0;
    let nowHight = 0;
    //当前顶部高度
    let nowMarginTop = 0;
    //获取弹框头部（这部分可双击全屏）
    const dialogHeaderEl = el.querySelector(".el-dialog__header");
    //弹窗
    const dragDom = el.querySelector(".el-dialog");
    //给弹窗加上overflow auto；不然缩小时框内的标签可能超出dialog；
    dragDom.style.overflow = "auto";
    //清除选择头部文字效果
    //dialogHeaderEl.onselectstart = new Function("return false");
    //头部加上可拖动cursor
    dialogHeaderEl.style.cursor = "move";
    // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
    const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);
    let moveDown = e => {
      // 鼠标按下，计算当前元素距离可视区的距离
      const disX = e.clientX - dialogHeaderEl.offsetLeft;
      const disY = e.clientY - dialogHeaderEl.offsetTop;
      // 获取到的值带px 正则匹配替换
      let styL, styT;
      // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
      if (sty.left.includes("%")) {
        styL =
          +document.body.clientWidth * (+sty.left.replace(/\%/g, "") / 100);
        styT =
          +document.body.clientHeight * (+sty.top.replace(/\%/g, "") / 100);
      } else {
        styL = +sty.left.replace(/\px/g, "");
        styT = +sty.top.replace(/\px/g, "");
      }
      document.onmousemove = function(e) {
        // 通过事件委托，计算移动的距离
        const l = e.clientX - disX;
        const t = e.clientY - disY;
        // 移动当前元素
        dragDom.style.left = `${l + styL}px`;
        dragDom.style.top = `${t + styT}px`;
        //将此时的位置传出去
        //binding.value({x:e.pageX,y:e.pageY})
      };
      document.onmouseup = function(e) {
        document.onmousemove = null;
        document.onmouseup = null;
      };
    };
    dialogHeaderEl.onmousedown = moveDown;
    //双击头部全屏效果
    dialogHeaderEl.ondblclick = e => {
      if (isFullScreen == false) {
        nowHight = dragDom.clientHeight;
        nowWidth = dragDom.clientWidth;
        nowMarginTop = dragDom.style.marginTop;
        dragDom.style.left = 0;
        dragDom.style.top = 0;
        dragDom.style.height = "100VH";
        dragDom.style.width = "100VW";
        dragDom.style.marginTop = 0;
        isFullScreen = true;
        dialogHeaderEl.style.cursor = "initial";
        dialogHeaderEl.onmousedown = null;

      } else {

        dragDom.style.height = "auto";

        dragDom.style.width = nowWidth + "px";

        dragDom.style.marginTop = nowMarginTop;

        isFullScreen = false;

        dialogHeaderEl.style.cursor = "move";

        dialogHeaderEl.onmousedown = moveDown;

      }

    };

    dragDom.onmousemove = function(e) {

      let moveE = e;

      if (

        e.clientX > dragDom.offsetLeft + dragDom.clientWidth - 10 ||

        dragDom.offsetLeft + 10 > e.clientX

      ) {

        dragDom.style.cursor = "w-resize";

      } else if (

        el.scrollTop + e.clientY >

        dragDom.offsetTop + dragDom.clientHeight - 10

      ) {

        dragDom.style.cursor = "s-resize";

      } else {

        dragDom.style.cursor = "default";

        dragDom.onmousedown = null;

      }

      dragDom.onmousedown = e => {

        const clientX = e.clientX;

        const clientY = e.clientY;

        let elW = dragDom.clientWidth;

        let elH = dragDom.clientHeight;

        let EloffsetLeft = dragDom.offsetLeft;

        let EloffsetTop = dragDom.offsetTop;

        dragDom.style.userSelect = "none";

        let ELscrollTop = el.scrollTop;

        //判断点击的位置是不是为头部

        if (

          clientX > EloffsetLeft &&

          clientX < EloffsetLeft + elW &&

          clientY > EloffsetTop &&

          clientY < EloffsetTop + 100

        ) {

          //如果是头部在此就不做任何动作，以上有绑定dialogHeaderEl.onmousedown = moveDown;

        } else {

          document.onmousemove = function(e) {

            e.preventDefault(); // 移动时禁用默认事件

            //左侧鼠标拖拽位置

            if (clientX > EloffsetLeft && clientX < EloffsetLeft + 10) {

              //往左拖拽

              if (clientX > e.clientX) {

                dragDom.style.width = elW + (clientX - e.clientX) * 2 + "px";

              }

              //往右拖拽

              if (clientX < e.clientX) {

                if (dragDom.clientWidth < minWidth) {

                } else {

                  dragDom.style.width = elW - (e.clientX - clientX) * 2 + "px";

                }

              }

            }

            //右侧鼠标拖拽位置

            if (

              clientX > EloffsetLeft + elW - 10 &&

              clientX < EloffsetLeft + elW

            ) {

              //往左拖拽

              if (clientX > e.clientX) {

                if (dragDom.clientWidth < minWidth) {

                } else {

                  dragDom.style.width = elW - (clientX - e.clientX) * 2 + "px";

                }

              }

              //往右拖拽

              if (clientX < e.clientX) {

                dragDom.style.width = elW + (e.clientX - clientX) * 2 + "px";

              }

            }

            //底部鼠标拖拽位置

            if (

              ELscrollTop + clientY > EloffsetTop + elH - 20 &&

              ELscrollTop + clientY < EloffsetTop + elH

            ) {

              //往上拖拽

              if (clientY > e.clientY) {

                if (dragDom.clientHeight < minHeight) {

                } else {

                  dragDom.style.height = elH - (clientY - e.clientY) * 2 + "px";

                }

              }

              //往下拖拽

              if (clientY < e.clientY) {

                dragDom.style.height = elH + (e.clientY - clientY) * 2 + "px";

              }

            }

          };

          //拉伸结束

          document.onmouseup = function(e) {

            document.onmousemove = null;

            document.onmouseup = null;

          };

        }

      };

    };

  }

});
